There are numerous reasons as to why one refund may be approved and processed more quickly than others...everything from verifying one's identity or financial institution processing times, to validation of an individual's credits/deductions claims and who prepared the return. If it was prepared by HR Block, for example, refund delays can occur due to reasons such as having the prep fees withheld from a refund- requiring the refund to first be deposited into their account, with their financial institution's processing timeframe..for both receiving said refund, deducting fees, and then transferring your refund). There can also be other banking delays that could impact the date the refund is received. Unfortunately, the process for the IRS approving and depositing refunds is based on several factors that can impact just how long it takes.
I would suggest tracking it on the IRS "Where's my refund" tool to see exactly when they estimate you'll receive it. It will also provide a date for how long to wait before investigating why it has yet to be received. It's recommended that you begin with contacting your bank and then calling the IRS after they confirm it isn't delayed by them. The IRS may not be as willing to help until it has reached that date.
Where's My Refund? tool:
https://sa.www4.irs.gov/irfof/lang/en/irfofgetstatus.jsp
